Francesco Chiabrera

IREC Catalonia Institute for Energy Research | IREC · Department of Advanced Materials for Energy

Perovskite oxides form a large family of materials with applications across various fields, owing to their structural and chemical flexibility. Efficient exploration of this extensive compositional space is now achievable through automated high‐throughput experimentation combined with machine learning. In this study, we investigate the composition–...

Metal nanoparticle exsolution from metal oxide hosts has recently garnered great attention to improve the performance of energy conversion and storage devices. In this study, the nickel exsolution mechanisms in a vertically aligned nanostructure (VAN) thin film of heteroepitaxial (Sr0.9Pr0.1)0.9Ti0.9Ni0.1O3−δ-Ce0.9Gd0.1O1.95 with a columnar archite...

The exploitation of advanced materials for novel energy, health, and computing applications requires deep insight and fundamental understanding of physicochemical mechanisms, such as ionic and electronic conductivity, defect formation processes, and reaction kinetics. Therefore, access to the underlying constants of the functional materials via adv...

Ferroionic materials combine ferroelectric properties and spontaneous polarization with ionic phenomena of fast charge recombination and electrodic functionalities. In this paper, we propose the concept of tunable polarization in CeO2−δ (ceria) thin (5 nm) films induced by built-in remnant polarization of a BaTiO3 (BTO) ferroelectric thin film inte...

Switchability of materials properties by applying controlled stimuli such as voltage pulses is an emerging field of study with applicability in adaptive and programmable devices like neuromorphic transistors or non-emissive smart displays. One of the most exciting approaches to modulate materials performance is mobile ion/vacancy insertion for indu...

Neuromorphic hardware facilitates rapid and energy-efficient training and operation of neural network models for artificial intelligence. However, existing analog in-memory computing devices, like memristors, continue to face significant challenges that impede their commercialization. These challenges include high variability due to their stochasti...

Functional properties of mixed ionic electronic conductors (MIECs) can be radically modified by (de)insertion of mobile charged defects. A complete control of this dynamic behaviour has multiple applications in a myriad of fields including advanced computing, data processing, sensing or energy conversion. However, the effect of different MIECs stat...

Perovskite oxides (ABO3) represent a large family of materials with wide application in many fields due to their celebrated structural and chemical flexibility. Such a vast space of compositions requires efficient exploration strategies now possible with automated high-throughput experiments combined with machine learning prediction algorithms. In...

Perovskite oxides (ABO3) represent a large family of materials with wide application in many fields due to their celebrated structural and chemical flexibility. Such a vast space of compositions requires efficient exploration strategies now possible with automated high-throughput experiments combined with machine learning prediction algorithms. In...

The implementation of nanocomposite materials as electrode layers represents a potential turning point for next-generation of solid oxide cells in order to reduce the use of critical raw materials. However, the substitution of bulk electrode materials by thin films is still under debate especially due to the uncertainty about their performance and...

The ability to perform both electrochemical and structural/elemental characterization in the same experiment and at the nanoscale allows to directly link electrochemical performance to the material properties and their evolution over time and operating conditions. Such experiments can be important for the further development of solid oxide cells, s...

We have developed a novel in situ methodology for the direct study of mass transport properties in oxides with spatial and unprecedented time resolution, based on Raman spectroscopy coupled to isothermal isotope exchanges. Changes in the isotope concentration, resulting in a Raman frequency shift, can be followed in real time, not accessible by con...

Ion intercalation of perovskite oxides in liquid electrolytes is a very promising method for controlling their functional properties while storing charge, which opens the potential application in different energy and information technologies. Although the role of defect chemistry in the oxygen intercalation in a gaseous environment is well establis...

The concept of combining electrical impedance spectroscopy (EIS) with environmental transmission electron microscopy (ETEM) is demonstrated by testing a specially designed micro gadolinia‐doped ceria (CGO) sample in reactive gasses (O2 and H2/H2O), at elevated temperatures (room temperature—800 °C) and with applied electrical potentials. The EIS‐TE...

We have developed a novel in situ methodology for the direct study of mass transport properties in oxides with spatial and unprecedented time resolution, based on Raman spectroscopy coupled to isothermal isotope exchanges. Changes in the isotope concentration, resulting in a Raman frequency shift, can be followed in real time, not accessible by con...

Developing reliable methods for modulating the electronic structure of the 2D electron gas (2DEG) in SrTiO3 is crucial for utilizing its full potential and inducing novel properties. Herein, it is shown that relatively simple surface preparation reconstructs the 2DEG at the SrTiO3 (STO) surface, leading to a Lifshitz‐like transition. Combining expe...

Internet-of-thing (IoT) is an assembly of devices that collect and share data with other devices and communicate via the internet. This massive network of devices, generates and communicates data and is the key to the value in IoT, allowing access to raw information, gaining insight, and making an intelligent decisions. Today, there are billions of...

CO2 reduction in Solid Oxide Electrolysis Cells (SOECs) is a key-technology for the transition to a sustainable energy infrastructure and chemical industry. Ceria (CeO2) holds great promise in developing highly efficient, cost-effective and durable fuel electrodes, due to its promising electrocatalytic properties, and proven ability to suppress car...

Oxygen mass transport in perovskite oxides is relevant for a variety of energy and information technologies. In oxide thin films, cation nonstoichiometry is often found but its impact on the oxygen transport properties is not well understood. Here, we used oxygen isotope exchange depth profile technique coupled with secondary ion mass spectrometry...

The use of nanostructured interfaces and advanced functional materials opens up a new playground in the field of solid oxide fuel cells. In this work, we present two all-ceramic thin-film heterostructures based on samarium-doped ceria and lanthanum strontium chromite manganite as promising functional layers for electrode application. The films were...

Along with recent advancements in thin-film technologies, the engineering of complex transition metal oxide heterostructures offers the possibility of creating novel and tunable multifunctionalities. A representative complex oxide is the perovskite strontium titanate (STO), whose bulk form is nominally a centrosymmetric paraelectric band insulator....

The integration of dissimilar materials in heterostructures has long been a cornerstone of modern materials science – seminal examples are the two‐dimensional (2D) materials and van der Waals heterostructures. Recently, new methods have been developed, which enable the realization of ultra‐thin freestanding oxide films approaching the 2D limit. Oxi...

Developing reliable methods for modulating the electronic structure of the two-dimensional electron gas (2DEG) in SrTiO3 is crucial for utilizing its full potential and inducing novel properties. Here, we show that relatively simple surface preparation reconstructs the 2DEG of SrTiO3 (STO) surface, leading to a Lifshitz-like transition. Combining e...

In this review paper, recent progress in the fabrication, transfer, and fundamental physical properties of freestanding oxide perovskite thin films is discussed. First, the main strategies for the synthesis and transfer of freestanding perovskite thin films are analyzed. In this initial section, particular attention is devoted to the use of water-s...

Combining angle-resolved photoemission spectroscopy and density functional theory calculations, we addressed the surface electronic structure of bent SrTiO3 (STO) (001) wafers. Using a custom-made device, we observe that the low-dimensional states that emerge at the STO (001) surface are robust to an external tensile strain of about 0.1%. Our resul...

The call for material systems with enhanced mass transport properties is central in the development of next-generation fuel cells, batteries and solid state energy devices in general. While two-dimensional doping by artificial heterostructuring or nanoscaling has shown great potential for overcoming kinetic limitations of ion diffusion, the length...

Tuning oxygen mass transport properties at the nanoscale offers a promising approach for developing high performing energy materials. A number of strategies for engineering interfaces with enhanced oxygen diffusivity and surface exchange have been proposed. However, the origin and the magnitude of such local effects remain largely undisclosed to da...

High temperature solid oxide solar cells based on SrTiO3 (STO) are investigated. Schottky contacts between STO and different materials, including La1-xSrxCrO3, La0.8Sr0.2MnO3, La0.6Sr0.4CoO3 and metals like Au and Pt are illuminated by UV light with a wavelength of 365 nm at 350 °C in air and the resulting voltages and currents are measured. With c...

Tuning oxygen mass transport properties at the nanoscale offers a promising approach for developing high performing energy materials. A number of strategies for engineering interfaces with enhanced oxygen diffusivity and surface exchange has recently been proposed. However, the origin and the local magnitude of such local effects remain largely und...

Tuning oxygen mass transport properties at the nanoscale offers a promising approach for developing high performing energy materials. A number of strategies for engineering interfaces with enhanced oxygen diffusivity and surface exchange has recently been proposed. However, the origin and the local magnitude of such local effects remain largely und...

Unveiling point defects concentration in transition metal oxide thin films is essential to understand and eventually control their functional properties, employed in an increasing number of applications and devices. Despite this unquestionable interest, there is a lack of available experimental techniques able to estimate the defect chemistry and e...

A novel non-destructive methodology for operando observation of ion intercalation and the state of charge on battery electrodes is presented based on spectroscopic ellipsometry (SE). The potentiality of this technique for performing time-resolved measurements of (de-)lithiation processes on electrode materials has been demonstrated using thin film...

The implementation of nano-engineered composite oxides opens up the way towards the development of a novel class of functional materials with enhanced electrochemical properties. Here we report on the realization of vertically aligned nanocomposites of lanthanum strontium manganite and doped ceria with straight applicability as functional layers in...

The defect chemistry of La1−xSrxFeO3−δ (LSF) thin films is unveiled for intermediate‐to‐low temperature range using a novel in situ ellipsometry approach. The evolution of the concentration of holes in the LSF thin films with oxygen partial pressure and temperature is obtained. This technique pushes the limits for tracking the defect chemistry in L...

Unveiling point defects concentration in transition metal oxide thin films is essential to understand and eventually control their functional properties, employed in an increasing number of applications and devices. Despite this unquestionable interest, there is a lack of available experimental techniques able to estimate the defect chemistry and e...

div>The implementation of nano-engineered composite oxides opens up the way towards the development of a novel class of superior energy materials. Vertically aligned nanocomposites are characterized by a coherent, dense array of vertical interfaces, which allows for the extension of local effects to the whole volume of the material. Here, we use...

The implementation of nano-engineered composite oxides opens up the way towards the development of a novel class of superior energy materials. Vertically aligned nanocomposites are characterized by a coherent, dense array of vertical interfaces, which allows for the extension of local effects to the whole volume of the material. Here, we use such a...

A novel non-destructive methodology for operando observation of ion intercalation and the state of charge on battery electrodes is presented based on spectroscopic ellipsometry (SE). The potentiality of this technique for performing time-resolved measurements of (de-)lithiation processes on electrode materials has been demonstrated using thin film...

Stabilized bismuth vanadate thin films are presented here as superior oxide ionic conductors, for application in solid state electrochemical devices operating near room temperature. Widely studied in the 90´s in bulk form due to their unbeatable ionic conduction, this family of materials was finally discarded due to poor stability above 500 ºC. Her...

Grain boundaries of strontium‐doped lanthanum manganite thin films are characterized by Albert Tarancón and co‐workers in article number 1805360, by a strong modification of both the anionic and cationic composition. The grain‐boundary local nonstoichiometry can be altered by tuning the overall cationic content in the thin films, offering a tool to...

Grain boundaries in Sr-doped LaMnO3±δ thin films have been shown to strongly influence the electronic and oxygen mass transport properties, being able to profoundly modify the nature of the material. The unique behavior of the grain boundaries can be correlated with substantial modifications of the cation concentration at the interfaces, which can...

Interface-dominated materials such as nanocrystalline thin films have emerged as an enthralling class of materials able to engineer functional properties of transition metal oxides widely used in energy and information technologies. In particular, it has been proven that strain-induced defects in grain boundaries of manganites deeply impact their f...

The behavior of interface-dominated metal-oxide thin films is largely influenced by nanoionic effects. The control and engineering of interfaces becomes a powerful tool for the design of optimized electrochemical devices, in which ion movement plays a primary role. This chapter provides a comprehensive description of the most relevant ionic phenome...

Ion transport in solid-state devices is of great interest for current and future energy and information technologies. A superior enhancement of several orders of magnitude of the oxygen diffusivity has been recently reported for grain boundaries in lanthanum-strontium manganites. However, the significance and extent of this unique phenomenon are no...

Portable electronic devices are already an indispensable part of our daily life; and their increasing number and demand for higher performance is becoming a challenge for the research community. In particular, a major concern is the way to efficiently power these energy-demanding devices, assuring long grid independency with high efficiency, sustai...

Strontium-doped lanthanum manganite thin films were deposited by pulsed laser deposition on yttria-stabilized zirconia single crystals for a comprehensive electrochemical characterization of the material acting as a cathode. A physically-meaningful electrical model was employed to fit the electrochemical impedance spectroscopy results in order to e...

New emerging disciplines are specifically devoted to study trivial and non-trivial effects resulting from working in the nanoscale, however, the implementation of these nanostructures in real devices is still a major challenge. Thin film deposition and silicon microtechnology is probably the most promising and straightforward combination for the re...

New emerging disciplines are specifically devoted to study trivial and non-trivial effects resulting from working in the nanoscale, however, the implementation of these nanostructures in real devices is still a major challenge. Thin film deposition and silicon microtechnology is probably the most promising and straightforward combination for the re...